1. Field of the Invention
The present invention relates to a vehicle control device and a vehicle control method for a vehicle that can execute free-run traveling.
2. Description of the Related Art
In a hybrid vehicle, when acceleration is requested during EV traveling in which an engine is stopped and a clutch is disengaged, the engine is re-started and the clutch is engaged. At this time, to promptly increase a rotation speed of the engine, a part of drive torque of a motor is used. Therefore, when the clutch is engaged, a driver might have difficulty in feeling the sense of acceleration and drivability may be deteriorated due to lack of the drive torque. In view of the circumstances, Japanese Patent Application Laid-open No. 2012-201194 has proposed a technique in which an output torque is transmitted to a drive wheel by upshifting of continuously variable transmission, the output torque being obtained such that inertia torque of the continuously variable transmission is added to the drive torque of the motor, so that the deterioration of the drivability is suppressed.
By the way, a vehicle is conventionally known, which can execute free-run traveling in which the engine is stopped and the clutch is disengaged when the acceleration is not requested during traveling. Suppression of the deterioration of the drivability can be considered by applying of the technique disclosed in Japanese Patent Application Laid-open No. 2012-201194 to such a vehicle, when the vehicle returns from the free-run traveling state to a normal traveling state in which the engine is started and the clutch is engaged, in response to an acceleration request. However, at this time, when the vehicle does not include a motor, the vehicle cannot increase the rotation speed of the engine using the drive torque of the motor, and thus requires a lot of time to start the engine, compared with a hybrid vehicle. Accordingly, when the vehicle returns from the free-run traveling state to the normal traveling state, a lot of time is required to re-accelerate the vehicle by the engine. Therefore, when the vehicle that can execute the free-run traveling does not include the motor, the deterioration of the drivability cannot be suppressed when the vehicle returns from the free-run traveling state to the normal traveling state even if the technique disclosed in Japanese Patent Application Laid-open No. 2012-201194 is applied to the vehicle.
There is a need for a vehicle control device and a vehicle control method, which can suppress the deterioration of the drivability when the vehicle returns from the free-run traveling state to the normal traveling state.